// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2016 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_SPECIALFUNCTIONS_PACKETMATH_H
#define EIGEN_SPECIALFUNCTIONS_PACKETMATH_H

namespace Eigen {

namespace internal {

    /** \internal \returns the ln(|gamma(\a a)|) (coeff-wise) */
    template <typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet plgamma(const Packet& a)
    {
        using numext::lgamma;
        return lgamma(a);
    }

    /** \internal \returns the derivative of lgamma, psi(\a a) (coeff-wise) */
    template <typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet pdigamma(const Packet& a)
    {
        using numext::digamma;
        return digamma(a);
    }

    /** \internal \returns the zeta function of two arguments (coeff-wise) */
    template <typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet pzeta(const Packet& x, const Packet& q)
    {
        using numext::zeta;
        return zeta(x, q);
    }

    /** \internal \returns the polygamma function (coeff-wise) */
    template <typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet ppolygamma(const Packet& n, const Packet& x)
    {
        using numext::polygamma;
        return polygamma(n, x);
    }

    /** \internal \returns the erf(\a a) (coeff-wise) */
    template <typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet perf(const Packet& a)
    {
        using numext::erf;
        return erf(a);
    }

    /** \internal \returns the erfc(\a a) (coeff-wise) */
    template <typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet perfc(const Packet& a)
    {
        using numext::erfc;
        return erfc(a);
    }

    /** \internal \returns the ndtri(\a a) (coeff-wise) */
    template <typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet pndtri(const Packet& a)
    {
        typedef typename unpacket_traits<Packet>::type ScalarType;
        using internal::generic_ndtri;
        return generic_ndtri<Packet, ScalarType>(a);
    }

    /** \internal \returns the incomplete gamma function igamma(\a a, \a x) */
    template <typename Packet> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pigamma(const Packet& a, const Packet& x)
    {
        using numext::igamma;
        return igamma(a, x);
    }

    /** \internal \returns the derivative of the incomplete gamma function
 * igamma_der_a(\a a, \a x) */
    template <typename Packet> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pigamma_der_a(const Packet& a, const Packet& x)
    {
        using numext::igamma_der_a;
        return igamma_der_a(a, x);
    }

    /** \internal \returns compute the derivative of the sample
  * of Gamma(alpha, 1) random variable with respect to the parameter a
  * gamma_sample_der_alpha(\a alpha, \a sample) */
    template <typename Packet> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pgamma_sample_der_alpha(const Packet& alpha, const Packet& sample)
    {
        using numext::gamma_sample_der_alpha;
        return gamma_sample_der_alpha(alpha, sample);
    }

    /** \internal \returns the complementary incomplete gamma function igammac(\a a, \a x) */
    template <typename Packet> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pigammac(const Packet& a, const Packet& x)
    {
        using numext::igammac;
        return igammac(a, x);
    }

    /** \internal \returns the complementary incomplete gamma function betainc(\a a, \a b, \a x) */
    template <typename Packet> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pbetainc(const Packet& a, const Packet& b, const Packet& x)
    {
        using numext::betainc;
        return betainc(a, b, x);
    }

}  // end namespace internal

}  // end namespace Eigen

#endif  // EIGEN_SPECIALFUNCTIONS_PACKETMATH_H
